can a car battery have enough power to crank over for a couple seconds, but not have enough power to get the engine started? because that is what my car is doing now...

 

Get a voltmeter and check the voltage on the battery. Should be close to a 12.7, if it's in the 11's, looking at a dead battery. But the fact that it's cranking let's me believe that the problem might not be with the battery. Does it sound like it cranks normally or does it sound like it cranks slow?

 

could be alot of things, but sounds to me like your alternator.